KConfigSkeletonItem : allow to set a KconfigGroup to read and write items in nested groups

Summary:
Currently KConfgiSkeleton cannot manage item entry in subgroup, like

```
[General][Colors]
MyItem=foo
```

Example of use

```
// Generated Class with KConfig compiler, inherits KConfigSkeleton

KConfigGroup generalGroup( &config, "General" );
KConfigGroup colorsGroup = config.group( "Colors" )
myItem->setGroup(cg); // Now can take a KConfigGroup
addItem(myItem, "MyItem");

```

Evolution of kconfig compiler will follow to consider this.

Reviewers: ervin, dfaure, #frameworks, mdawson

Reviewed By: ervin, dfaure

Subscribers: kde-frameworks-devel

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D27059

1 files changed, 26 insertions, 2 deletions

diff --git a/src/core/kcoreconfigskeleton.h b/src/core/kcoreconfigskeleton.h
index 7abc4052..02473fb4 100644
--- a/src/core/kcoreconfigskeleton.h
+++ b/src/core/kcoreconfigskeleton.h
@@ -34,6 +34,7 @@
 #include <QStringList>
 #include <QVariant>
 #include <QUrl>
+
 class KCoreConfigSkeletonPrivate;
 
 class KConfigSkeletonItemPrivate;
@@ -82,6 +83,22 @@ public:
     QString group() const;
 
     /**
+     * Set config file group but giving the KConfigGroup.
+     * Allow the item to be in nested groups.
+     * @since 5.68
+     */
+    void setGroup(const KConfigGroup &cg);
+
+    /**
+     * Return a KConfigGroup, the one provided by setGroup(KConfigGroup) if it's valid,
+     * or make one from @param config and item's group
+     * @sa setGroup(const QString &_group)
+     * @sa setGroup(KConfigGroup cg)
+     * @since 5.68
+     */
+    KConfigGroup configGroup(KConfig *config) const;
+
+    /**
      * Set config file key.
      */
     void setKey(const QString &_key);
@@ -366,7 +383,7 @@ public:
     void writeConfig(KConfig *config) override
     {
         if (mReference != mLoadedValue) { // Is this needed?
-            KConfigGroup cg(config, mGroup);
+            KConfigGroup cg = configGroup(config);
             if ((mDefault == mReference) && !cg.hasDefault(mKey)) {
                 cg.revertToDefault(mKey, writeFlags());
             } else {
@@ -436,10 +453,17 @@ public:
     QVariant property() const override;
     void setDefault() override;
     void swapDefault() override;
-    // shadow the method in KConfigSkeletonItem, which should be fine for autogenerated code
     // KF6 TODO - fix this
+    // Ideally we would do this in an overload of KConfigSkeletonItem, but
+    // given we can't, I've shadowed the method. This isn't pretty, but given
+    // the docs say it should generally only be used from auto generated code,
+    // should be fine.
     void setWriteFlags(KConfigBase::WriteConfigFlags flags);
     KConfigBase::WriteConfigFlags writeFlags() const;
+    void setGroup(const KConfigGroup &cg);
+    KConfigGroup configGroup(KConfig *config) const;
+    // END TODO
+
 private:
     inline void invokeNotifyFunction()
     {